Re: Human mind Turing computable according to Eliezer

From: Jef Allbright (
Date: Fri Oct 08 2004 - 09:42:23 MDT

Wei Dai wrote:

>Let me try this approach to the issue, and see if it's helpful. Consider
>the following thought experiment. You're a disembodied brain living in a
>jar, with remote control of a telepresence robot. You just heard that the
>storage warehouse housing your jar is on fire, and rush the robot back
>to save yourself. The bad news is there are thousands of brains in the
>warehouse, and you don't know which one is yours. The good news is there's
>a brain scanning machine with resolution down to individual neurons, and
>you can try to use it to find out which brain is you. Question is, how to
>do it?
>How do you take a bunch of neurons and figure out what it's experiencing?
>Would the answer to this question also answer Mitchell's question, or is
>he asking something else?
>Is this question worth trying to answer? A mind with full access to its
>self-state presumably wouldn't have this problem with determining which
>brain is itself. It would just directly compare the scanner output with
>its own self-inspection. Assuming that we'll get this feature soon,
>is there some other scenario where the answer would be useful?
We have methods (MRI, for example), that allow us to correlate some
physical brain activity with some conscious experience. In the
hypothetical warehouse on fire, the problem of identification could be
as simple as consciously driving motor control in a unique timing
pattern and looking for the brain with a matching pattern of neuronal

But what people get hung up on is that they see this mechanistic
description of brain activity and still want to know "where" the "real
self" is in this picture. Where's the experiencing happening?

The answer is that it's one of those cases where the question is wrong.
The experiencing is not happening in any exalted location within the
brain, and there is no separate "self" to have the experience. It's a
mechanistic system that has a capability for limited introspection --
awareness of being aware. The usual way it has to "experience" itself
is through its own internal mechanisms which naturally report back in
terms that are perceived and recorded as real and complete.

However, we now have less subjective ways to observe the functioning of
our brains and their environment. Our instruments show us that the
processing of the brain and the human perceptual system has many gaps,
distortions, discontinuities, etc., that are not apparent to the system
we think of as Self.

We now have very substantial information obtained through scientific
observation and reasoning showing us that our conventional sense of self
is an illusion, but since we are immersed in this illusion, and our
evolved nature is to instinctively protect this Self, and our culture
and language support this illusion, it is difficult for many people to
fully consider.

In my opinion, a dualistic approach to living is most effective,
applying either the subjective stance or the objective stance as
appropriate to the situation. Wisdom consists in knowing which and when.

- Jef

This archive was generated by hypermail 2.1.5 : Wed Jul 17 2013 - 04:00:49 MDT